When assisting train is pulling the disabled train, what is the powering and braking set up?

In scenarios where an assisting train is pulling a disabled train, the configuration for powering and braking is crucial for ensuring safety and efficiency during the operation. When the assisting train powers, it provides the necessary momentum to move both trains, while also managing the braking system as needed.

Option C indicates that the assisting train both powers and brakes. This is accurate because when the assisting train is engaged in this scenario, it must exert power to move the disabled train, which would typically require the assisting train to apply brakes effectively to control the speed of both trains.

This setup allows the assisting train to manage the dynamics of the movement, ensuring that both trains operate cohesively. The ability to brake is also essential to prevent excessive speed and to maintain control, particularly when navigating gradients or when approaching stations. Hence, having the assisting train take on both roles of powering and braking supports a safer and more controlled operation in this context.